Devices for supporting the lumbar region of the back are well known to those skilled in the art. Thus, for example, U.S. Pat. No. 4,597,386 of Goldstein describes a cushion comprising a plurality of juxtaposed segments retained in mutually supporting engagement with each other by a cover. The device of this patent, however, is not integral and, thus, cannot be used without its cover. Furthermore, such device, because its has substantially uniform stiffness properties in the lateral direction, does not provided adequate cushioning locally for the bony protuberances of the spinal column.
U.S. Pat. No. 4,161,337 of Ross et al. provides a portable orthopedic seat unit insert which is comprised of two separate, spaced-apart, padded, generally elliptical back support members, and a substantially vertically rigid conecting member joining them together. However, the vertically rigid connecting member of this patent does not provide any support at all for the spinal column.
U.S. Pat. No. 3,856,349 of Light discloses (at column 1) that, ". . . during prolonged sitting the lower back, at rest, gradually assumes the curvature of the material it is resting against, and, if this is a cushion or a curved seat back, the person's natural lordosis is accentuated." The device of this patent is comprised of a substantially flat and elongated pad which is relatively rigid throughout the complete length thereof. However, the device of this patent does not provide adequate cushioning to lumbar region of the back and, furthermore, artificially constrains the back into an unnatural and uncomfortable position.
U.S. Pat. No. 4,471,993 of Watson describes a device for supporting the low back area of the body comprising a front resilient member and an inner core. The device of this patent, because its has substantially uniform stiffness properties in the lateral direction, does not provided adequate cushioning locally for the bony protuberances of the spinal column. Furthermore, because of the dimensions and the configuration of the device of this patent, one using it is pushed forward in the seat and thus cannot utilize all of the support afforded by the entire length of the seat bottom with most conventional chairs.
It is an object of this invention to provide a lower back support cushion which, when in place on the back of a seating surface or device, provides support to the curvature of the lower back while simultaneously alleviating local pressure on the bony protuberances of the spinal column.
It is another object of this invention to provide lower-back support cushion with arcuate curvature so adapted, when it is used by a patient, will allow him to utilze substantially all of the support afforded by the length of the seat bottom.
It is another object of this invention to provide an integral, multi-layered cushion which may be used without a cover.
It is yet another object of this invention to provide a means for removably and adjustably attaching the back cushion of this invention to a seating device.
It is yet another object of this invention to provide a back cushion whose use tends to insure correct lateral placement of the spinal column in the lower back region.